Class 7 Science Chapter 18 MCQ

Class 7 Science Chapter 18 MCQ (Multiple Choice Questions) of Wastewater Story in English Medium updated for CBSE Session 2021-2022. All the questions are important and useful of terminal exams and class tests.

MCQs are design in such a way it covers the entire chapter 18 of class 7 science. There are about 60 questions in all divided into 10 MCQ online tests.

Class 7 Science Chapter 18 MCQ for 2021-2022

Class: 7Science
Chapter: 18Wastewater Story
Contents: MCQ Online Quiz with answers

MCQ Tests with Answers for Class 7 Science Chapter 18


Which of the following is wastewater?

[A]. Water trickling from a damaged tap
[B]. Water coming out of a shower
[C]. Water flowing in a river
[D]. Water coming out of a laundry

Consider the following statements and choose the incorrect one:

[A]. Clean water is a basic necessity of our life.
[B]. The wastewater may also contain pieces of human excreta.
[C]. Use water or waste water could not be reused after cleaning it.
[D]. The cleaning of water is a process of removing pollutants harmful substances from it.

Sewage is mainly a:

[A]. Liquid waste
[B]. Solid waste
[C]. Gaseous waste
[D]. Mixture of solid and gas

Which of the following is or are products of wastewater treatment?

[A]. Biogas
[B]. Sludge
[C]. Both biogas and sludge
[D]. Aerator

Open drain system is a breeding place for which of the following?

[A]. Flies
[B]. Mosquitoes
[C]. Organisms which cause disease
[D]. All the above


Water polluted by various human activities cause a number of water-borne diseases. Which of the following is not a water-borne disease?

[A]. Cholera
[B]. Typhoid
[C]. Asthma
[D]. Dysentry

Pick from the following one chemical which is used to disinfect water?

[A]. Chlorine
[B]. Washing soda
[C]. Silica
[D]. Coal

Which of the following statement is or are correct?

[A]. Water that is fit for use and safe for drinking is known as clean water.
[B]. The dissolved and suspended impurities present in water are called contaminants.
[C]. The gas that is produced by decomposition of sludge by the anaerobic bacteria is known as biogas.
[D]. All the above.

The system of a network of pipes used for taking away wastewater from homes or public buildings to the treatment plant is known as

[A]. Sewers
[B]. Sewerage
[C]. Transport system
[D]. Treatment plant

Which of the following is a part of inorganic impurities of the sewage?

[A]. Pesticides
[B]. Urea
[C]. Phosphate
[D]. Vegetable waste


Gunja is completed her science chapter where she wrote some statements. She wants to know whether the statements are correct or not? Gunja wants to take help from you:

[A]. The wastewater or sewage entering the sewage treatment plant is the first passed through bar screens.
[B]. The wastewater passing through the bar screen is made to flow slowly through a tank called “grit and sand removal tank”.
[C]. The sludge is taken out from the bottom of first sedimentation tank and put into a large, closed tank called “digester tank”.
[D]. None of the above.

In a filtration plant, water is filtered using layers of:

[A]. Sand and clay
[B]. Clay and fine gravel
[C]. Sand and fine gravel
[D]. Sand, fine gravel and medium gravel

Select the one that is incorrect for wormy processing toilet:

[A]. It is a new method and has been recently tested in India.
[B]. In it the human excreta are treated by cockroaches and round worms.
[C]. In it the human excreta are completely converted into vermi-cakes.
[D]. It is an ideal, low water use toilet that is safe for processing of human waste.

Which of the following is a good practice be followed?

[A]. Cooking oil and paint should not be thrown down a drain.
[B]. Used tea leaves, solid food and cotton should not be thrown in the drain.
[C]. Chemicals like insecticides should not throw in the drain.
[D]. All of the above

Which of the following is not a source of wastewater?

[A]. Sewers
[B]. Homes
[C]. Industries
[D]. Hospitals


The General Assembly of United Nation on the World Water Day on 22nd march 2005 has declared the period as the international decade for action on:

[A]. Water for Life
[B]. Nature for Water
[C]. Water and Disaster
[D]. Water for Future

Which of the following is not an inorganic impurity present in sewage?

[A]. Nitrate
[B]. Phosphate
[C]. Urea
[D]. Metal salt

In this year board examination, Ajju were asked a question where he had to choose the statement which was/were correct? Will you be able to answer this question?

[A]. World Water Day 2020, on 22 March, is about water and climate change.
[B]. The theme of 2019 was about tackling the water crisis by addressing the reasons why so many people are being left behind
[C]. In 2017, the theme was “Why Waste Water?” which was about reducing and reusing wastewater.
[D]. All the above

Which of the following can be used to disinfect the clean water in a sewage treatment plant before releasing it into the distribution system?

[A]. Iodine and Ozone
[B]. Ozone and Oxygen
[C]. Ozone and Chlorine
[D]. Chlorine only

Which of the following is not a water-borne disease?

[A]. Cholera
[B]. Tuberculosis
[C]. Typhoid
[D]. Dysentery


Recently, in a science class test, you are asked a question where you have to say whether the statements are correct or not?

[A]. Untreated human excreta is a health hazard.
[B]. The untreated human excreta cause soil pollution and water pollution.
[C]. More than one billion people in the world do not get safe drinking water.
[D]. None of the above

Which of the following statement is or are incorrect?

[A]. All the portable toilets are chemical toilets.
[B]. Septic tanks and composting pits are called on-site sewage facility.
[C]. Septic tanks are suitable for those places where there is no sewage system.
[D]. The human waste can not be used in a biogas plant for making biogas.

The examples of onsite sewage disposal system for human waste are:

[A]. Septic tanks
[B]. Composting pits and
[C]. Chemical toilets.
[D]. All the above

In a quiz competition, you are asked a question where you have to choose the statement which is/ are incorrect?

[A]. Poor sanitation in crowded public places can result in the spread of diseases.
[B]. Open dirty water drains are breeding place for flies, mosquitoes and other disease-causing organisms.
[C]. If all the wastes produced at public places are not disposed at of regularly and properly, even epidemics could break out.
[D]. Only the responsibility of the municipality of the area to maintain sanitization or hygienic condition.

Which of the following are used for the safe disposal of human excreta in those areas where sewerage system does not exist and water supply is limited or not available at all?

[A]. Chemical toilets
[B]. Vacuum toilets
[C]. Septic tank toilets
[D]. Composting toilets

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